This invention relates to transducer mountings, and particularly, to an assembly for attaching transducers to containers for fluids.
The use of ultrasonic transducers with fluids such as solvents in a cleaning tank, molten solder in a tinning pot, and similar liquid systems in a container has been a problem from the standpoint of reliability, energy transfer and assembly methods due to the usual methods of attaching transducers to fluid containers. The usual method now used in this art for attaching transducers to containers is to attach a transducer adhesively or metallurgically to containers of liquids to be vibrated. Adhesive attachments have been lacking in reliability because of their inherent low mechanical endurance limits, thermal stress fracturing and incompatibility with liquid solvents leading to reduced coupling or complete detachment of the transducer or transducers. Metallurgically attached transducers have been found to have a relatively high degree of reliability insofar as attachment is concerned. However, the high brazing or welding temperatures produce warping and incompatibility changes, reducing mechanical endurance limits of the container, and resulting in fatigue and the like.
A method is now known, and embodied in this invention, that eliminates the problems of the prior art discussed hereinabove. Previous inventions couple the output of the transducer or transducers directly to the fluid to be vibrated, with the transducer attachment to the container being at a low particle displacement plane of a composite transducer, by mechanically sandwiching the container wall at the plane desired. The disadvantage of this method is that the direct attachment causes the wall of the container to vibrate. The lower frequency harmonics of the wall oscillation reduces the efficiency of the ultrasonic transducer, and thereby results in a waste of energy.